Manila: At least 44 people, including school children were killed on Monday after a severe 6.8 magnitude quake hit the third-largest island in the Philippines and causing buildings to collapse and shutting down power supply.

The quake struck about 70 kilometers from the coastal city of Dumaguete on the Philippine island of Negros, the US Geological Survey said.

The dead included two elementary school children, authorities said, according to the Philippines News Agency.

The girls died when walls at their schools collapsed on them, National Police spokesman Chief Supt. Agrimero Cruz Jr. said.

"The death toll from a strong earthquake that jolted central Philippine province of Negros Oriental on Monday morning rose to 44, a military official was quoted as saying by a media report.

The earthquake also caused cracked walls and shattered windows in a department store on Negros, said Balido, the military assistant for operations at the civil defense office.

The Philippine Institute of Volcanology and Seismology issued a level 2 tsunami alert for areas along the Tanon Strait between Negros and the neighboring island of Cebu.

The alert -- a notch below the highest tsunami alert of level 3, which required evacuation of the affected areas -- was later lifted after an observation period, according to the Philippines News Agency.

No tsunami warning was issued for the wider Pacific region, and there was no tsunami threat to Hawaii, the Pacific Tsunami Warning Center said.

The earthquake occurred in the ocean at a depth of 46.6 kilometers, according to the USGS.

The Philippines is situated in the so-called Ring of Fire, an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.

At the Circle Inn Hotel in the city of Bacolod, which is on Negros but not on the coast nearest the quake's epicenter, a receptionist said the quake lasted between three and five minutes.

"We felt the shaking," the receptionist said. "The guests all exited the building. But all the people here are okay." There was no damage to the hotel, the receptionist was quoted as saying by CNN.

The main quake was felt at Intensity 7 in Dumaguete and Sibulan, Intensity 8 in Tanjay City and stronger intensities in the northern towns, said Science research analyst Engineer Jose Agustin Molas of the Philippine Institute of Volcanology and Seismology (PHIVOLCS) Seismic Station in San Antonio.

According to Molas, the main shock lasted for about 402.32 seconds or 6.7 minutes from start to finish based on the seismograph recording. However, people interviewed said they felt the tremor from less than a minute to up to two or three minutes depending on their location.

Five aftershocks, concluding one measuring six magnitude immediately followed. By 2 pm, at least 80 aftershocks were recorded at the Sibulan PHIVOLCS Seismic Station. By 5 pm Molas reported a total of 157 aftershocks even as people in Dumaguete and other nearby areas were posting on social networking sites of feeling slight tremors, the PNA said.

Shortly after 1 pm, a tsunami alert level 2 warning was issued by PHIVOLCS Cebu, causing panic among residents in Dumaguete and other areas and sending people evacuating to higher ground, specifically in the mountainous areas of Sibulan and Valencia towns.

Businesses rolled to a stop, department stores, the Robinson's Place shopping mall and other business establishments closed for the day as people scrambled to leave for their homes. Traffic piled up in Dumaguete as pedicabs, the main form of transportation, became scarce.

The northern parts of Negros Oriental were the hardest hit with several buildings that had collapsed, roads and bridges destroyed and rendered impassable and landslides reported in some areas.